package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.FOLLOWS;

/**
*@Author: X_x
*@Date: 2024-08-27-11-43
*@Description:  * @param null
*@return:
*@tags: 梦想和爱 健康和学习
*/
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;
    /**
     * 关注和取关
     * @param followUserId=》关联的用户id 即被关注的博主id
     */
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //1.获取用户
        Long userId = UserHolder.getUser().getId();
        String key = FOLLOWS + userId;
        //2.判断是关注还是取关
        if (isFollow) {
            //3.关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if (isSuccess) {
                //把关注的用户id放入Redis的set集合  sadd userId followUserId
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
            //4.取关，删除 delete from tb_follow where user_id = ? and follow_user_id = ?
            boolean isSuccess = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", followUserId));
            if (isSuccess) {
                //把关注的用户id从Redis set集合移除
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }
        }
        return Result.ok();
    }
    /**
     * 查询是否关注
     */
    @Override
    public Result isFollow(Long followUserId) {
        //1.获取用户
        Long userId = UserHolder.getUser().getId();
        //2.查询是否关注
        //select count(*) from tb_follow where user_id = ? and follow_user_id = ?
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        //3.判断
        return Result.ok(count > 0);
    }
    /**
     * 共同关注
     * @param id
     * @return
     */
    @Override
    public Result followCommons(Long id) {
        //1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key = FOLLOWS + userId;//userId 其他用户id
        String key1 = FOLLOWS + id;//id 当前用户id（本人）
        //2.求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key1);
        if (intersect == null || intersect.isEmpty()) {
            //没有交集，返回一个空集合
            return Result.ok(Collections.emptyList());
        }
        //3.解析id集合
        //使用stream流处理解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //4.查询用户
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(users);
    }
}
